M-TCP: Using Disconnection Feedback to Improve Performance of TCP in Wired/Wireless Networks

In this paper, we propose the M-TCP algorithm for heterogeneous wired/wireless networks. The algorithm is a modification of M-TCP that was proposed for deployment in mobile cellular networks. It is recommended that Internet hosts enable the delayed acknowledgement (delayed ACK) option to maximize network bandwidth by reducing the number of ACKs sent to a TCP sender by a TCP receiver. The M-TCP algorithm performs best when the TCP delayed ACK option is enabled. The algorithm relies on feedback sent from a wireless host in anticipation of disconnections. We compare the performance of the MTCP algorithm with the performance of M-TCP, TCP NewReno, and TCP SACK in both the absence and the presence of disconnections for a file transfer protocol (download) application. We also simulate network scenarios with traffic congestion. The M-TCP algorithm performance is evaluated in terms of file download response time, goodput, and retransmission ratio, with and without the delayed ACK option. In scenarios without disconnections, the M-TCP algorithm does not introduce significant processing delay. Furthermore, in scenarios with disconnections, the M-TCP algorithm shows 2%–15% performance improvement.